drm/i915/bios: add intel_bios_dp_max_link_rate()

Don't access i915->vbt.ddi_port_info[] directly.
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/8c30e1183afdd469c95b01f64ca0458b9e832404.1579270868.git.jani.nikula@intel.com

drivers/gpu/drm/i915/display/intel_bios.c

@@ -2592,3 +2592,10 @@ int intel_bios_hdmi_boost_level(struct intel_encoder *encoder)
 
 	return i915->vbt.ddi_port_info[encoder->port].hdmi_boost_level;
 }
+
+int intel_bios_dp_max_link_rate(struct intel_encoder *encoder)
+{
+	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
+
+	return i915->vbt.ddi_port_info[encoder->port].dp_max_link_rate;
+}

drivers/gpu/drm/i915/display/intel_bios.h

@@ -251,5 +251,6 @@ int intel_bios_max_tmds_clock(struct intel_encoder *encoder);
 int intel_bios_hdmi_level_shift(struct intel_encoder *encoder);
 int intel_bios_dp_boost_level(struct intel_encoder *encoder);
 int intel_bios_hdmi_boost_level(struct intel_encoder *encoder);
+int intel_bios_dp_max_link_rate(struct intel_encoder *encoder);
 
 #endif /* _INTEL_BIOS_H_ */

drivers/gpu/drm/i915/display/intel_dp.c

@@ -323,11 +323,10 @@ intel_dp_set_source_rates(struct intel_dp *intel_dp)
 		162000, 270000
 	};
 	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
+	struct intel_encoder *encoder = &dig_port->base;
 	struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
-	const struct ddi_vbt_port_info *info =
-		&dev_priv->vbt.ddi_port_info[dig_port->base.port];
 	const int *source_rates;
-	int size, max_rate = 0, vbt_max_rate = info->dp_max_link_rate;
+	int size, max_rate = 0, vbt_max_rate;
 
 	/* This should only be done once */
 	WARN_ON(intel_dp->source_rates || intel_dp->num_source_rates);
@@ -354,6 +353,7 @@ intel_dp_set_source_rates(struct intel_dp *intel_dp)
 		size = ARRAY_SIZE(g4x_rates);
 	}
 
+	vbt_max_rate = intel_bios_dp_max_link_rate(encoder);
 	if (max_rate && vbt_max_rate)
 		max_rate = min(max_rate, vbt_max_rate);
 	else if (vbt_max_rate)